Remus felt much the same, though at times he felt guilty. Especially knowing what he knew now about Peter and the truth about what had happened with James, Lily, Sirius, and the whole Fidelius charm situation. If he went back, he could try to dig up some evidence that Peter had been a Death Eater, that Peter had been the one who betrayed James and Lily to Voldemort, that Peter was likely the one responsible for the deaths of those Muggles and he'd set Sirius up to take the fall -- Sirius could walk free. It was very hard not to let that eat away at him day in and day out. Sometimes, it did. And those were times he left their shared dwelling and went for walks, so he could let himself feel that pain but not put it on Sirius. Maybe that wasn't right or entirely honest, but he didn't want Sirius to think that it had anything to do with him or what they were doing together now.
Now was all they had. They might very well never leave his place. And if they didn't, Remus was happy to be there with him. He was happy they were finally getting this all right and elated that in owning up to their feelings they'd found the sort of joy that was indescribable in words. No amount of guilt or worry of being selfish could overshadow the immense happiness he felt in being with Sirius now, where they were.
When Sirius took his shirt off, Remus couldn't help but drink in the sight of him as though he'd been wandering in the desert for days without water. It obviously wasn't the first time he'd seen him in a state of undress. They'd lived together for a good portion of their lives. They'd woken up from full moons in various states of undress. But it wasn't like this. He ran both hands up along Sirius' smooth skin along his sides and back. "You're a right sight, and I know you know it," he said, grinning. Remus was a little hesitant in taking his own shirt off. He wasn't smooth and beautiful; his skin was marred with raised lines from jagged gashes that had scarred over here and there; bite marks from his own teeth littered here and there, tarnishing his body. And there were more than what this Sirius was probably used to, but even at nineteen, he'd know. Now wasn't the time to be afraid or self conscious.
Remus pushed up enough to pull his shirt off too, letting it join Sirius' in a forgotten heap on the floor. He pulled Sirius back down, skin to skin, and kissed him deeply again.